Intermediate Coupling Model of the Cuprates

TL;DR

This paper reviews an intermediate coupling model for cuprates, demonstrating its ability to accurately reproduce various spectroscopic features across different doping levels and states, bridging weak and strong coupling regimes.

Contribution

It introduces a robust, material-specific GW-based framework for modeling cuprates that captures doping and temperature effects with minimal parameters, extending to multi-band correlated systems.

Findings

Model reproduces ARPES, STM/STS, neutron scattering data

Captures doping and temperature dependence of spectra

Bridges weak and strong coupling regimes in cuprates

Abstract

We review the intermediate coupling model for treating electronic correlations in the cuprates. Spectral signatures of the intermediate coupling scenario are identified and used to adduce that the cuprates fall in the intermediate rather than the weak or the strong coupling limits. A robust, `beyond LDA' framework for obtaining wide-ranging properties of the cuprates via a GW-approximation based self-consistent self-energy correction for incorporating correlation effects is delineated. In this way, doping and temperature dependent spectra, from the undoped insulator to the overdoped metal, in the normal as well as the superconducting state, with features of both weak and strong coupling can be modeled in a material-specific manner with very few parameters. Efficacy of the model is shown by considering available spectroscopic data on electron and hole doped cuprates from angle-resolved photoemission (ARPES), scanning tunneling microscopy/spectroscopy (STM/STS), neutron scattering, inelastic light scattering, optical and other experiments. Generalizations to treat systems with multiple correlated bands such as the heavy-fermions, the ruthenates, and the actinides are discussed.